Structural and biochemical methods will be used to characterize amyloid-Uke fibrils of SODl and its segments. The overall goals are to understand the process of fibrillation of SODl in vitro and in cells, and to determine atomic structures for the fibril-defining segments of SODl. This informatin will be used in the process of structure-based design, to create inhibitors of fibrillation of SODl and its mutants. These inhibitors can be lead compounds for drugs against SODl fibrillation and possibly fALS. A high-risk goal is to characterize the structure of SODl aggregates that form in human cells [see Project 3). In particular, micro-X-ray diffraction will be used to assess the possibility that SODl is in the amyloid state in cells.